O-alkylhydroxylamines have been prepared by reacting oximes with alkyl halides under basic conditions to give O-alkyl oximes, followed by acid catalyzed hydrolysis of the O-alkyl oxime. For example, PCT Application WO 8911473 discloses a process for producing O-substituted oxime compounds in which a large excess of propanone oxime in toluene is reacted with an aqueous alkali metal hydroxide to give, after azeotropic distillation, the oxime salt which on reaction with an alkyl halide followed by further distillation, acidification and extraction with toluene affords the O-alkyl oxime in moderate purity (83.5%). European Pat. No. 85-103052 discloses a similar process for the synthesis of O-alkyl oximes which were subsequently hydrolysed using aqueous hydrochloric acid to give the O-alkylhydroxylamines.
Jap. Pat. No. 03258757 discloses a process in which acetone oxime is reacted with sodium hydride and N,N-dimethylformamide at 60.degree.to 70.degree. C. and the resulting oxime salt subsequently reacted with an alkyl bromide to give a low yield (37%) of an O-alkyl acetone oxime. Jap. Pat. No. 83-68791 discloses a similar process in which the acetone oxime salt is generated below 10.degree. C. and subsequently reacted with a solution of an alkyl halide in dimethoxyethane to give a low yield (52.4%) of an O-alkyl oxime.
German Pat. No. 86-3631071 discloses a procedure for the preparation of O-substituted hydroxylamine hydrochlorides in which a O-alkyl acetone oxime, present in a mixture of 1,4-dioxane, water and hydrochloric acid, is hydrolysed and the acetone continuously removed by distillation through a bubble tray column.
The above methods suffer from one or more disadvantages such as isolation of intermediates which is inconvenient and costly, low yields and use of undesirable solvents. In contrast, the present invention uses a process which does not require isolation of intermediates, produces high yields of the O-alkyl oximes and their O-alkylhydroxylamine derivatives, and requires only one organic solvent which can be recovered and reused.
The process of the present invention for preparing O-alkylhydroxylamines is represented as follows: ##STR1##